CVE-2011-5245 in RESTEasy
Summary
by MITRE
The readFrom function in providers.jaxb.JAXBXmlTypeProvider in RESTEasy before 2.3.2 allows remote attackers to read arbitrary files via an external entity reference in a Java Architecture for XML Binding (JAXB) input, aka an XML external entity (XXE) injection attack, a similar vulnerability to CVE-2012-0818.
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Analysis
by VulDB Data Team • 12/27/2024
The vulnerability identified as CVE-2011-5245 represents a critical XML external entity injection flaw within the RESTEasy framework's JAXB provider implementation. This security weakness exists in the readFrom function of providers.jaxb.JAXBXmlTypeProvider component, which processes JAXB input data within RESTEasy versions prior to 2.3.2. The vulnerability enables remote attackers to exploit the framework's XML processing capabilities by manipulating external entity references, thereby allowing unauthorized access to arbitrary files on the server system. This type of attack leverages the fundamental behavior of XML parsers that automatically resolve external entity references during document processing, creating a pathway for attackers to access sensitive system resources.
The technical exploitation of this vulnerability occurs through the manipulation of XML input that contains external entity declarations referencing local files. When RESTEasy processes such malformed XML input through its JAXB provider, the framework fails to properly validate or sanitize external entity references, allowing the XML parser to resolve these references and potentially read files from the local filesystem. This flaw operates at the core of XML processing within the Java ecosystem, where the underlying JAXB implementation does not adequately restrict access to external resources during parsing operations. The vulnerability is classified as an XXE injection attack pattern that directly maps to CWE-611, which specifically addresses Improper Restriction of XML External Entity Reference.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can potentially enable attackers to access sensitive configuration files, database credentials, system logs, and other confidential data stored on the server. Remote attackers can leverage this vulnerability to perform reconnaissance activities, escalate privileges, or gain unauthorized access to additional system resources. The attack vector requires only the ability to send XML input to the RESTEasy application, making it particularly dangerous in web applications that accept user-supplied XML data. This vulnerability affects the integrity and confidentiality of applications using RESTEasy, as it allows attackers to bypass normal access controls and directly access server-side resources. The impact is particularly severe in environments where RESTEasy applications process untrusted XML input from external sources, as the vulnerability can be exploited without requiring authentication or privileged access.
Security mitigations for this vulnerability primarily focus on updating to RESTEasy version 2.3.2 or later, which includes proper validation and sanitization of external entity references in the JAXB processing pipeline. Organizations should also implement XML parser configuration changes that disable external entity resolution entirely, particularly when processing untrusted input. Additional protective measures include input validation and sanitization at multiple layers, implementing proper access controls, and monitoring for suspicious XML processing activities. The remediation approach aligns with ATT&CK technique T1213, which addresses Data from Information Repositories, as the vulnerability enables unauthorized access to system resources that would otherwise be protected. Security teams should also consider implementing web application firewalls that can detect and block XXE attack patterns, along with comprehensive logging and monitoring to identify potential exploitation attempts. Organizations utilizing RESTEasy frameworks must ensure proper security configuration of XML processing components and maintain up-to-date dependencies to prevent exploitation of similar vulnerabilities in the broader Java ecosystem.